HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Radin, J. W. Articles by Sell, C. R. Search for Related Content PubMed Articles by Radin, J. W. Articles by Sell, C. R. Agricola Articles by Radin, J. W. Articles by Sell, C. R.

Growth of Cotton Plants on Nitrate and Ammonium Nitrogen¹

Vegetative and reproductive growth of cotton (Gossypium hirsutum L.) were evaluated in the greenhouse on media containing nitrate or ammonium or both, to test for interactions between the two N sources on growth and yield. An inhibitor of nitrification was included in all treatments. Both N sources supported vegetative growth, although there was little response to increments of nitrate above meq/liter under the conditions of the test. Combinations of the two N sources did not support better growth than either one alone, except at low total N levels, perhaps because ammonium at 2 meq/liter inhibited in vivo nitrate reductase activity.

Reproductive growth of the plants was enhanced by N; however, 9 meq/liter nitrate was less effective than lower concentrations of either source, or their combination, in promoting fruitfulness and N accumulation relative to the vegetative parts. The failure to find a synergistic interaction in response to the two sources suggests that cotton responds to N source differently from some other crop species.

Key Words: Leaf area • Relative Growth rate • Nitrate reductase • Gossypium hirsutum L. • N-Serve®

² Plant physiologist and physical sciences technician, respectively, ARS, Western Cotton Res. Lab., 4135 E. Broadway Rd., Phoenix, AZ 85040.

Received for publication January 10, 1975.